A thermosetting furan resin composition which contains a furan resin composed of a co-condensation product of furfuryl alcohol and formaldehyde can make a cured product excellent in heat resistance, solvent resistance, and chemical resistance, and is conventionally used as steel pipe lining, joint cement, and a matrix resin for a laminate or composite material such as FRP or the like, in various industrial fields.
As such a thermosetting furan resin composition, PTL1 discloses a thermosetting furan resin composition which contains a furan resin obtained from a reaction of furan or a furan derivative and an aldehyde in the presence of an acid catalyst.